Sighting device



E A. EVERETT SIGHTING DEVICE filed Jan. 18. 192i 2 Sheets-Sheet 2 I J k /////////////r//9 i INVEN TOR. iwz lwxfi BY Y Patented Apr; 3, 1928.

UNITED STATES EDWARD A. EVERETT, OF NEW YORK, N. Y.

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Application filed January 18, 1926. Serial ili'o. 82,156.

This invention relates to sighting devices for accurately determining the location of an object and is illustrated in application to railway signals of the light type wherein the beam of light from the signal is projected in a predetermined direction and the source of illumination is located with relation to the focal point of a lens. The invention comprises a detachable sighting device for the housing of the si nalb means of which the signal may be a juste ,to project the beam of light in a predetermined direction, also, it comprises a novel type of sighting tube which is particularly adapted for sighting an illuminated object at close range. These and other objects of the invention will be more particularly understood from the following specification and the accompanying drawings, in which, Fig. 1 is a sectional elevation of vention, Fig. 2 is' a plan view from the top of the lamp shown in Fig. 1, Fig. 3 is a sectional elevation looking from the rear end towards the lens, Fig. 4 is asighting tube in section constructed according'to my inven-.

tion and Fig. 5 is an end view of the sighting tube at the end opposite the eye piece.

In the art of'railway signaling the use of electric lights for illuminating the signal indication has become quite general. These lights are obtained from low voltage bulbs which are ener 'zed from a primary or storage battery an in order to economize on the batter consumption the illumination is limite In order to obtain the maximum results from the light under these conditions it. is necessary that the source of light be positioned accurately at the focal centre of the lens and that the beam of.light from the signal be properly directed along the track. These results are obtained in the present disclosure in asimple and practical manner.

Referring to the drawings, 11 is the hous- -ing of the signal device which is made of'a unitary casting with an aperture in the top covered by the circular cover 12 which is clamped in place by the. bar 16 pivoted at 17, secured to the cover at.18 and clamped by the wing nut 19 on the eye bolt 38 through the jaws 39 of bar 16. This construction is substantially the same as my co-pending application Serial No. 60,899, filed Oct. 6, 1925.

The base of the housing is adjustably supported through a socket 13 bay1 a bracket arm such as shown in the 'co-pen 'ng application a signal lamp embodying my in ture is closed by a cap.

referred to. The lens 14 is secured in a turned recess in the casting and held in place by'the lens ring 15.

The signal is-illustrated by the lamp bulb 21 through the concentrated filament 22. Th1s bulb is supported by a'base 23 secured to a plate 24 which is adjustably positioned by the ad usting screws 25. This adjustable support for the lamp bulb is similar to that shown in -U. S. Patent 1,535,218, issued in my name on April 28, 1925, and further description is not deemed necessary in this case except to note that the filament of the lamp bulb is adjustable in all directions with reference to the axis of the lens 14. The conductors for the circuit of the lamp bulb are led through a block of insulation 29 and the terminals are accessible through the detachable cover 30. t

The rear wall of the housing 11'is provided with a cast boss 27 which is drilled at 28 to form a sighting tube and to which the reflector 26 is screwed or attached at the inner end. Another boss'is cast in this wall at 31 and is drilled to receive a tube or stem 32 and is threaded at the outer end to receive a cap or cover.

The ste 32 is a snug fit in 31 and carries the arm 3 with the head 34 which clamps the sighting tube 35 having the eye piece 36. It is apparent that the arm 33 is rotatable upon the stem 32 as a centre and mayswing in an arc across the top of the housing: This device is detachable, being inserted in aperture 31 for use and when removed, this aper- In Fi 3 another sighting device 41 is shown w ich is accessible when the cover 12 is removed, the support ofthis device iscast integral with the housing.

Anovel type of sighting tube as shown in Figs. 4 and 5 is'used in practicing my invention. This has a tubular body 35 to which the Eeye piece 43 is secured and which clamps theicup shaped member 45 in place. This member-has a'small central aperture at 46 in line with the aperture 44- in the eye piece.

The opposite end of the sig closed by a glass disc 42 wh1ch may be secured by spinning over the'end of t e tube, by a ring or by other means wellunderstood in this art. This disc is provided with a series of concentric rings as at 47 by means of which the sight is located.

In surveying instruments it is. common hting tube is and intercepts the sight on the filament and may entirely obscure the filament. By the arrangement of concentric rings in the end of the sighting tube an accurate sight on the filament can be taken When it is illuminated. The sight through the eye piece covers the spread between the lines 9, the stand of the bulb is then adjusted until the filament is brought within the circles and until, eventually, it is brought into the centre of the disc. These rings may be made of lines of different widths as indicated with the thicker lines preferably towards the centre. The rings enable the eye to readily .27 being 'jigged to secure this result. The.

determine the direction of adjustment required and to determine when the-centre has been reached. It should be noted that the rings are easily applied to the disc-when the tube is set up in a lathe by bringing a diamond cutter into contact with the glass.

In this construction it will be observed that the tube 28 drilled in the housing at 27 is in line with the axial centre of .the lens 14, the recess for the lens and the drill for boss 13 for the ivot of the supporting bracket is also drilled with relation to the axial centre of the lens to be perpendicular to and intercept this centre.

The axial centre of the lens is indicated by the line aa assing through the centre of tube 28. A slght can be taken on this line from the outside of the housing. The boss 31 in the housing is drilled parallel to 28 so that the line 6-6 is parallel to line aa and the arm 33 and head 34 hold the sighting tube 35 with its axis c--'c parallel to b-b. It will thus be observed that while the sighting tube 35 is pivotably rotatable about the stem 32 it is always maintained parallel with the line aa and with the axial centre of the lens. The tube 35 is used for aligning the lam housing so that the beam of light projecte on the track will be in a redetermined direction. This tube is rotata 1e on stem 32 to clear local objects as for instance a semaphore spectacle that may be located in front of the lens 14. The vertical sup ort of the signal is pivoted on line d-d w ich intersects the line aa and the filament 22 so thatthe device may be rotated on this support without changing the relation of the lens, the filament and the bracket.

The sighting tube 28 is constructed similar totube 35 with the end disc having concentric rings which enables the filament, which is close to the end of the tube to be support.

In order to' determine the exact position of the filament back from the lens the sighting tube 41. is provided sighting the filament on line e e at right angles to line aa. This sighting device is enclosed by the cover 12.

Having thus described my invention, I

1. In a sighting device for a light projGCtOI', the combination, a housing with a projecting lens, a source of illumination in said housing, a sighting device in the Wall of said housing for locating said source 1n the axis of said lens, an arm supporting a of said housing for locating said source on the axis of said lens, a second sighting device at right angles to said axis for locating said source at the focus of said lens, an arm supporting a sighting tube for aligning said projector, a stem carrying said arm and a receptacle-in the wall of said housing olf-set from the axis of said lens for detachably supporting said stem.

3. In a system for sighting a source of illumination, the combination of a tube closed at one end with a non-transparent disc having a, sight hole in the centre thereof and closed at the opposite end with a disc of glass, said glass disc having a circle of comparatively broad lines inscribed about the centre thereof and located comparatively close to the source of illumination.

4. In a system for sighting a source of illumination, the combination of a tube closed at one end with a non-transparent disc having a sight hole in the centre thereof and closed at the opposite end with a disc of glass, said glass disc havin a .plurality of circles, the innermost of w ich is formed of comparatively broad lines inscribed about the centre thereof and placed comparatively close to the source of illumi- EDWARD A. EVERETT.

70 properly sighted when adjusting the lamp 

